Cancer describes a class of diseases characterized by the uncontrolled growth of aberrant cells. It is the second leading cause of human death next to coronary disease. Worldwide, millions of people die from cancer every year. In the United States alone, cancer causes the death of well over a half-million people each year, with some 1.4 million new cases diagnosed per year.
One form of cancer, accounting for about 3% of all cancers in the United States of America, is leukemia. This malignant disease is characterised by an abnormal proliferation of white blood cells which can be detected in the peripheral blood and/or bone marrow. Leukemia can be broadly classified into acute and chronic leukemia. Acute leukemia can be subclassified into myeloid and lymphoid leukemia in a variety of ways, including cell morphology and cytochemistry.
Acute myeloid leukemia (AML) is the most common form of leukemia accounting for about 50% of all leukemia cases and even 85% of all acute leukemia cases involving adults. The standard treatment regime for AML is chemotherapy, which often includes an anthracycline. This results in a 70% complete remission (CR) rate in AML patients. Anthracycline therapy, however, is associated with severe side effects, including myelosuppression and dose-limiting cardiotoxicity, as well as a significant incidence of relapse. Less than 20% of CR patients survive in the long term. Relapsed AML disease exhibits multiple drug resistance (MDR), making the relapsed disease frequently refractory to further treatment with a variety of chemotherapeutic agents, including drugs.
In the light thereof novel therapies for AML have been developed. Some therapies make use of antibodies capable of binding to AML-associated antigens such as CD33 or CD45 (see WO 2004/043344). Although AML-associated antigens have been described, there is still a great need for new AML antigens useful in antibody and other biological therapies. In addition, there is a corresponding need for AML-associated antigens which may be useful as markers for antibody-based diagnostic and imaging methods, hopefully leading to the development of earlier diagnosis and greater prognostic precision.
The present invention addresses this need by providing new antigens useful in the prevention, treatment and diagnosis of tumors, in particular AML. Moreover, the present invention provides novel antibodies against these antigens.